In Sydney, a man in his sixties opened fire indiscriminately on passers-by.
According to police, he fired up to 50 shots from a .30-calibre rifle in the suburb of Croydon Park.
At least 20 people were injured in the shooting, one is in critical condition but is expected to survive.
Australian police have not yet found any connection between the incident and terrorism or religiously motivated crime.
Acting Superintendent Stephen Perry said the suspect has no known links to organised crime or terrorist groups known to law enforcement agencies.
